Democratic Republic of Congo Prime Minister Bruno Tshibala poses for a picture during an interview with Reuters in London, Britain March 7, 2018. Picture taken March 7, 2018. REUTERS/Marc Jones

By Helen Reid and Marc Jones

LONDON (Reuters) - An election in the Democratic Republic of Congo to replace President Joseph Kabila remains on course for late December, the central African country's Prime Minister, Bruno Tshibala, has said.

"I committed in front of our country's representatives in May last year to my mission which was to bring the Congolese people to elections this year, and I confirm that in December this year the Congolese people will be brought to the ballot boxes," Tshibala told Reuters in an interview late on Wednesday.

Repeated stalling of the election has raised tensions across the vast central African country, triggering street protests and encouraging armed rebellions. Kabila was due to step down when his mandate expired at the end of 2016 but has so far refused to do so.

"There were setbacks which caused this delay," said Tshibala. "But this time our course is set for elections and they will take place on December 23."

Tshibala, a former leading member of Congo's main opposition coalition, was appointed by Kabila just under a year ago to head a transitional 'unity' government tasked with organizing the election. He is expected to be the opposition candidate in the election.

When asked about technical problems experienced by voting machines during recent testing in the capital Kinshasa, Tshibala said: "Machines are a great revolution," adding they would help the election to run smoothly and in record time.

"We have taken all the precautions with the electoral commission for it to go well. It's true that it's a vast country... but that's exactly why the voting machines will help improve the process."

Opponents of current president Kabila, who has ruled Congo since his father’s assassination in 2001, suspect he intends to repeatedly delay elections until he can organize a referendum to let himself stand for a third term, as his counterparts in neighboring Congo Republic and Rwanda have done.

Kabila denies those charges, saying the election delays are due to challenges registering millions of voters and budgetary constraints.

DRC security forces have killed dozens of civilians in protests over election delays over the last two years. Worsening militia violence has meanwhile raised fears of a backslide toward the civil wars of the turn of the century that killed millions.

The country's economic situation is still difficult. The central bank currently predicts inflation of 38 percent for the end of 2018, and Tshibala said the country is prepared to cooperate with international financial institutions.

"We are making an internal effort to improve tax collection and government receipts," said Tshibala.

"If we find ourselves in a difficult situation we won't hesitate to speak to the international financial institutions to provide a supplement in order to improve our functioning as a state."

Congo, which is the same size as western Europe, has plentiful resources. It is Africa's largest copper producer and is the source of more than half the world's cobalt, a vital ingredient in mobile phone and electric vehicle batteries.

Its output jumped 15.5 percent last year and President Kabila held a nearly-six hour meeting with international mining companies on Wednesday on new mining laws that will increase the revenues DRC gets from the firms. [nL5N1QP71S]

"There will be a revision of the code to try and make it more attractive and fair to the DRC. There will be a compromise between us and the mining companies," Tshibala said.